This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-138727, filed May 9, 2001, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a switch box for a vehicle door apparatus having a powered door lock function.
2. Description of the Related Art
FIGS. 1 and 2 show the arrangement of part of a vehicle door lock device having a powered door lock function (see Jpn. Pat. Appln. KOKAI Publication No. 8-326387). Referring to FIGS. 1 and 2, a recess 2 is formed in the lower portion of the front surface of a synthetic-resin body 1 of the door lock device. A latch 3 and ratchet 4 are pivotally supported in the recess 2 by shafts 5 and 6, respectively.
The latch 3 is biased counterclockwise in FIG. 1 by a spring (not shown). Upon a door closing operation, when the latch 3 engages with a striker 7 fixed to the car body, it rotates counterclockwise. Hence, the latch 3 rotates to its full-latch state through a state (a so-called half-latch state) where it engages with its half-latch stepped portion 8.
A switch 34 is provided to abut against the side surface of the latch 3. The switch 34 detects the full-latch state of the latch 3 which engages with the striker 7 fixed to the car body side when the door is closed.
The switch 34 has an electrical switch mechanism which is ON when the latch is in the full-latch state. As shown in FIG. 1, most of the switch 34, excluding one end of its pin abutting against the side surface of the latch 3, is housed in an actuator housing chamber 20 which houses a powered actuator unit 17 (to be described later).
The actuator housing chamber 20 is surrounded by a base case 18 and a cover case (not shown). The base case 18 is integrally formed with the upper portion of the body 1. The cover case is fixed to the base case 18.
A lock lever (not shown) is axially supported by the latch shaft 5 and is switched between a lock position and unlock position. The actuator unit 17 in the actuator housing chamber 20 switches this lock lever between the lock position and unlock position.
FIG. 2 is a view schematically showing the actuator unit 17 housed in the actuator housing chamber 20 together with the switch 34. A gear 22 is fixed to the rotating shaft of a motor 21. A gear disk 23 meshes with the gear 22.
The gear disk 23 has a small-diameter gear 24 coaxial with it. A sector gear 25 rotatably axially supported by a shaft 26 meshes with the small-diameter gear 24.
The sector gear 25 is held at a neutral position at the center by a spring (not shown). When the motor 21 rotates in the forward or reverse direction, the sector gear 25 rotates clockwise or counterclockwise.
A projection 28 is formed on the distal end of a change lever 27 fixed to the shaft 26. The projection 28 engages with a wide recess 29 of the sector gear 25 with a lost motion linkage.
One end of the shaft 26 projects outward through the shaft hole of the cover case, and an output gear is fixed to this projecting portion. The output gear meshes with a gear portion formed on the lock lever.
The gear 22 fixed to the rotating shaft of the motor 21 rotates in the forward or reverse direction to rotate the gear disk 23. Then, the small-diameter gear 24 integrally formed with the gear disk 23 rotates the sector gear 25 within a predetermined range from the neutral position at the center.
Thus, the projection 28 of the change lever 27 engaging with the large-width recess 29 with the lost motion linkage engages with the sector gear 25 over the lost motion linkage and is rotated by it. Then, an output gear 31 fixed to the other end of the shaft 26 of the change lever 27 is rotated to pivot a lock gear 14 through its gear portion 32.
Therefore, the forward/reverse rotation of the motor 21 is transmitted to the lock lever (not shown) through a mechanism in the actuator unit 17. Thus, the lock lever is switched from the lock position to the unlock position or vice versa. After this, power supply to the motor 21 is ended and the rotational torque of the motor 21 disappears. Then, the sector gear 25 is automatically restored to the neutral position at the center by the elasticity of the spring.
As described above, the switch 34 is housed in the actuator housing chamber 20 together with the actuator unit 17. The distal end of the projecting pin of the switch 34 abuts against the side surface of the latch 3.
In the switch 34, one end of the pin biased by the spring projects to abut against the side surface of the latch 3, as described above. The other end of the pin is connected to an electrical contact piece which is ON when the latch 3 is in the full-latch state.
Since a vehicle door lock device is attached and fixed to the inner side of the steel plate of a vehicle door, it is adversely affected by the atmospheric temperature more easily than various types of components provided in the vehicle compartment.
The switch 34 is housed in the actuator housing chamber 20 together with other actuator unit 17 and the like. However, since the switch 34 particularly has an electric contact or the like, it may result in an operation failure due to dew condensation or the like.
It is an object of the present invention to provide a switch box for a vehicle door lock device, in which the adverse influence of dew condensation and the like caused by a temperature change is eliminated as much as possible so the operating state of a latch can be reliably detected under any condition.
A switch box for a vehicle door lock device for a vehicle door lock device, which is integrally housed in a lock body case and engages with and is fixed to a striker of a vehicle door, according to one aspect of the present invention is characterized by comprising: a slide pin which has one end abutting against a side surface of a latch that engages with and is fixed to the striker of a vehicle, and which slides in response to a pivot motion of the latch when biased by a spring; a slider which is connected and fixed to the other end of the slide pin and on which an elastic slide contact is disposed; a pair of terminals which are short-circuited to be connected to each other by the slide contact depending on a slide position of the slider; and a switch box cover which substantially hermetically covers most of the slide pin, excluding one end thereof abutting against the side surface of the latch, the spring, the slider, and the terminals in the lock body case, and the switch box cover has a through hole for ventilation at that position thereof which corresponds to a lower side of one side surface thereof when the switch box cover is attached to the vehicle door. The adverse influence of dew condensation and the like caused by a temperature change is eliminated as much as possible, so the operating state of the latch can be reliably detected under any condition.
Preferred manners of the switch box for a vehicle door lock device described above are as follows. The following manners may be used alone each, or may be appropriately combined.
(1) A path extending from the through hole for ventilation to an interior of the switch box is bent. The possibility that water may enter the switch box directly by any chance can be minimized.
(2) The switch box cover further has a through hole for drainage at that position thereof which corresponds to a lowermost end of one side surface of the switch box cover when the switch box cover is attached to the vehicle door. Water in the switch box can be drained immediately.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.